This project seeks to determine whether the regulation of lens fiber differentiation and maturation is associated with alterations in the plasma membrane. The composition, biosynthesis, and metabolism of lens lipids have been investigated using embryonic and adult chicken lenses, and cultured lens epithelial cells derived from the Nakano mouse. The relationships between phospholipid metabolism And differentiation have been studied in vivo and in vitro using isotopic labeling techniques and computer modeling. A decrease in the rate of phosphatidylinositol degradation and a transient increase in the rate of phospholipid methylation have been shown to accompany lens fiber formation. These alterations in membrane lipid metabolism are being correlated with other aspects of differentiation, such as cell elongation, protein phosphorylation, and the cessation of cell division.